I prefer to buy rotary blades in bulk from eBay. They seem to be considerably cheaper per blade that way, and I am still getting the good quality blades. I don't remember what I paid last time, but I think it came to something between $1 and $1.50 per blade. Haven't tried Harbor Freight blades, but they seem to have more problems than blades made specifically for my rotary cutter. The last thing I want to do is insert a new blade that doesn't work well fpr me.